This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The DNA helicase plays a very important role in the bacterial DNA replication and is responsible for the survival of the bacteria over the course of replication. There is no crystal structure information available to understand the conformation of this helicase or its mechanism of action. We requested time at a high-resolution beam line (NE-CAT 24ID) to complete the data collection of the SeMet derivative crystals of a bacterial DNA helicase and a bacteriophage single stranded DNA binding protein (SSB).